reserve i,j,k,n,m,l,s,t for Nat;
reserve a,b for Real;
reserve F for real-valued FinSequence;
reserve z for Complex;
reserve x,y for Complex;
reserve r,s,t for natural Number;

theorem Th47:
  m lcm n divides m*n
proof
  set s=m*n;
A1: n divides s by NAT_D:9;
  m divides s by NAT_D:9;
  hence thesis by A1,NAT_D:def 4;
end;
